<!DOCTYPE html>
<html>

<head>
    <title></title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link href="../bootstrap-5.1.3-dist/css/bootstrap.css" rel="stylesheet">
    <script src="../bootstrap-5.1.3-dist/js/bootstrap.bundle.min.js"></script>
</head>

<body class="container">
    <h3 align="center">设计导航栏的颜色</h3>
    <nav class="navbar navbar-expand-md navbar-dark bg-dark">
        <a class="navbar-brand me-auto" href="#">惠丰商城</a>
        <form class="d-flex">
            <input class="me-sm-2" type="search" placeholder="搜索热销电器">
            <button class="btn btn-outline-light me-sm-2 my-2 my-sm-0" type="submit">搜索</button>
        </form>
    </nav>
    <nav class="navbar navbar-expand-md navbar-dark bg-info my-2">
        <a class="navbar-brand me-auto" href="#">惠丰商城</a>
        <form class="d-flex">
            <input class="me-sm-2" type="search" placeholder="搜索热销水果">
            <button class="btn btn-outline-light me-sm-2 my-2 my-sm-0" type="submit">搜索</button>
        </form>
    </nav>
    <nav class="navbar navbar-expand-md navbar-light" style="background-color: #e3f3fd;">
        <a class="navbar-brand me-auto" href="#">惠丰商城</a>
        <form class="d-flex">
            <input class="me-sm-2" type="search" placeholder="搜索热销蔬菜">
            <button class="btn btn-outline-success me-sm-2 my-2 my-sm-0" type="submit">搜索</button>
        </form>
    </nav>
</body>

</html>